Try Missouri Star. I just bought a large tumbler template from them & it works beautifully! You can also make your own. Take a 5" square, cut from 1 bottom to 1" in on the top of the same side. Repeat on the other side and there you have it. There is also a great pattern on the quilterscache.com. You could just enlarge it to the size you'd like. Good luck. Let us know how you make out.